Support symlinks for git+http(s) dependencies

src/Package.zig

@@ -778,7 +778,7 @@ pub const ReadableResource = struct {
  .tar => try unpackTarball(allocator, prog_reader.reader(), tmp_directory.handle, dep_location_tok, report),
  .@"tar.gz" => try unpackTarballCompressed(allocator, prog_reader, tmp_directory.handle, dep_location_tok, report, std.compress.gzip),
  .@"tar.xz" => try unpackTarballCompressed(allocator, prog_reader, tmp_directory.handle, dep_location_tok, report, std.compress.xz),
- .git_pack => try unpackGitPack(allocator, &prog_reader, git.parseOid(rr.path) catch unreachable, tmp_directory.handle),
+ .git_pack => try unpackGitPack(allocator, &prog_reader, git.parseOid(rr.path) catch unreachable, tmp_directory.handle, dep_location_tok, report),
  }
  } else {
  // Recursive directory copy.
@@ -1220,6 +1220,8 @@ fn unpackGitPack(
  reader: anytype,
  want_oid: git.Oid,
  out_dir: fs.Dir,
+ dep_location_tok: std.zig.Ast.TokenIndex,
+ report: Report,
 ) !void {
  // The .git directory is used to store the packfile and associated index, but
  // we do not attempt to replicate the exact structure of a real .git
@@ -1251,7 +1253,32 @@ fn unpackGitPack(
  checkout_prog_node.activate();
  var repository = try git.Repository.init(gpa, pack_file, index_file);
  defer repository.deinit();
- try repository.checkout(out_dir, want_oid);
+ var diagnostics: git.Diagnostics = .{ .allocator = gpa };
+ defer diagnostics.deinit();
+ try repository.checkout(out_dir, want_oid, &diagnostics);
+
+ if (diagnostics.errors.items.len > 0) {
+ const notes_len: u32 = @intCast(diagnostics.errors.items.len);
+ try report.addErrorWithNotes(notes_len, .{
+ .tok = dep_location_tok,
+ .off = 0,
+ .msg = "unable to unpack packfile",
+ });
+ const eb = report.error_bundle;
+ const notes_start = try eb.reserveNotes(notes_len);
+ for (diagnostics.errors.items, notes_start..) |item, note_i| {
+ switch (item) {
+ .unable_to_create_sym_link => |info| {
+ eb.extra.items[note_i] = @intFromEnum(try eb.addErrorMessage(.{
+ .msg = try eb.printString("unable to create symlink from '{s}' to '{s}': {s}", .{
+ info.file_name, info.link_name, @errorName(info.code),
+ }),
+ }));
+ },
+ }
+ }
+ return error.InvalidGitPack;
+ }
  }
  }
 

src/git.zig

@@ -38,6 +38,32 @@ test parseOid {
  try testing.expectError(error.InvalidOid, parseOid("HEAD"));
 }
 
+pub const Diagnostics = struct {
+ allocator: Allocator,
+ errors: std.ArrayListUnmanaged(Error) = .{},
+
+ pub const Error = union(enum) {
+ unable_to_create_sym_link: struct {
+ code: anyerror,
+ file_name: []const u8,
+ link_name: []const u8,
+ },
+ };
+
+ pub fn deinit(d: *Diagnostics) void {
+ for (d.errors.items) |item| {
+ switch (item) {
+ .unable_to_create_sym_link => |info| {
+ d.allocator.free(info.file_name);
+ d.allocator.free(info.link_name);
+ },
+ }
+ }
+ d.errors.deinit(d.allocator);
+ d.* = undefined;
+ }
+};
+
 pub const Repository = struct {
  odb: Odb,
 
@@ -55,21 +81,24 @@ pub const Repository = struct {
  repository: *Repository,
  worktree: std.fs.Dir,
  commit_oid: Oid,
+ diagnostics: *Diagnostics,
  ) !void {
  try repository.odb.seekOid(commit_oid);
  const tree_oid = tree_oid: {
  var commit_object = try repository.odb.readObject();
  if (commit_object.type != .commit) return error.NotACommit;
  break :tree_oid try getCommitTree(commit_object.data);
  };
- try repository.checkoutTree(worktree, tree_oid);
+ try repository.checkoutTree(worktree, tree_oid, "", diagnostics);
  }
 
  /// Checks out the tree at `tree_oid` to `worktree`.
  fn checkoutTree(
  repository: *Repository,
  dir: std.fs.Dir,
  tree_oid: Oid,
+ current_path: []const u8,
+ diagnostics: *Diagnostics,
  ) !void {
  try repository.odb.seekOid(tree_oid);
  const tree_object = try repository.odb.readObject();
@@ -87,7 +116,9 @@ pub const Repository = struct {
  try dir.makeDir(entry.name);
  var subdir = try dir.openDir(entry.name, .{});
  defer subdir.close();
- try repository.checkoutTree(subdir, entry.oid);
+ const sub_path = try std.fs.path.join(repository.odb.allocator, &.{ current_path, entry.name });
+ defer repository.odb.allocator.free(sub_path);
+ try repository.checkoutTree(subdir, entry.oid, sub_path, diagnostics);
  },
  .file => {
  var file = try dir.createFile(entry.name, .{});
@@ -98,7 +129,23 @@ pub const Repository = struct {
  try file.writeAll(file_object.data);
  try file.sync();
  },
- .symlink => return error.SymlinkNotSupported,
+ .symlink => {
+ try repository.odb.seekOid(entry.oid);
+ var symlink_object = try repository.odb.readObject();
+ if (symlink_object.type != .blob) return error.InvalidFile;
+ const link_name = symlink_object.data;
+ dir.symLink(link_name, entry.name, .{}) catch |e| {
+ const file_name = try std.fs.path.join(diagnostics.allocator, &.{ current_path, entry.name });
+ errdefer diagnostics.allocator.free(file_name);
+ const link_name_dup = try diagnostics.allocator.dupe(u8, link_name);
+ errdefer diagnostics.allocator.free(link_name_dup);
+ try diagnostics.errors.append(diagnostics.allocator, .{ .unable_to_create_sym_link = .{
+ .code = e,
+ .file_name = file_name,
+ .link_name = link_name_dup,
+ } });
+ };
+ },
  .gitlink => {
  // Consistent with git archive behavior, create the directory but
  // do nothing else